title: Nonhydrolyzable ATP analogues as selective inhibitors of human NPP1: a combined computational/experimental study.
abstract: Elevated nucleotide pyrophosphatase/phosphodiesterase-1 (NPP1) activity is implicated in health disorders including pathological calcification. Specific NPP1 inhibitors would therefore be valuable for studying this enzyme and as potential therapeutic agents. Here we present a combined computational/experimental study characterizing 13 nonhydrolyzable ATP analogues as selective human NPP1 inhibitors. All analogues at 100 μM inhibited (66-99%) the hydrolysis of pnp-TMP by both recombinant NPP1 and cell surface NPP1 activity of osteocarcinoma (HTB-85) cells. These analogues only slightly altered the activity of other ectonucleotidases, NPP3 and NTPDases. The Ki,app values of the seven most potent and selective inhibitors were in the range of 0.5-56 μM, all with mixed type inhibition, predominantly competitive. Those molecules were docked into a newly developed homology model of human NPP1. All adopted ATP-like binding modes, suggesting competitive inhibition with the endogenous ligand. NPP1 selectivity versus NPP3 could be explained in terms of the electrostatic potential of the two proteins that of NPP1 favoring negatively charged ligands. Inhibitor 2 that had the lowest Ki,app (0.5 μM) was also inactive toward P2Y receptors. Overall, analogue 2 is the most potent and selective NPP1 inhibitor described so far.
authors.affiliation: Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval , Québec, QC G1V 0A6, Canada.
authors.forename: Joanna
authors.initials: J
authors.lastname: Lecka
authors.forename: Gal
authors.initials: G
authors.lastname: Ben-David
authors.forename: Luba
authors.initials: L
authors.lastname: Simhaev
authors.forename: Shay
authors.initials: S
authors.lastname: Eliahu
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Oscar
authors.forename: Patrick
authors.initials: P
authors.lastname: Luyindula
authors.forename: Julie
authors.initials: J
authors.lastname: Pelletier
authors.forename: Bilha
authors.initials: B
authors.lastname: Fischer
authors.forename: Hanoch
authors.initials: H
authors.lastname: Senderowitz
authors.forename: Jean
authors.initials: J
authors.lastname: Sévigny
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D006168:Guinea Pigs; D006801:Humans; D008958:Models, Molecular; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D010726:Phosphodiesterase Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D010727:Phosphoric Diester Hydrolases; D011755:Pyrophosphatases / Q000037:antagonists & inhibitors*; D016415:Sequence Alignment; D013329:Structure-Activity Relationship
chemical_list: D004791:Enzyme Inhibitors; D010726:Phosphodiesterase Inhibitors; D000255:Adenosine Triphosphate; D010727:Phosphoric Diester Hydrolases; C065962:ectonucleotide pyrophosphatase phosphodiesterase 1; D011755:Pyrophosphatases